Diego Gambetta is professor of social theory at the European University Institute, Florence, and official fellow of Nuffield College at the University of Oxford. His books include The Sicilian Mafia and Codes of the Underworld (Princeton). Steffen Hertog is associate professor of comparative politics at the London School of Economics. He is the author of Princes, Brokers, and Bureaucrats.

One of Foreign Affairs' Best Books on the Middle East (Terrorism & Counterterrorism) 2016 "This is an important study... The wealth of statistical data they bring to bear provides what was once a hypothesis with solid empirical grounding."--Malise Ruthven, Financial Times "[A]n interesting and important book... Definitely recommended."--Tyler Cowen, Marginal Revolution "That's really good work, and they deserve credit for that observation... It is thrilling and intriguing as a theoretical issue."--Jeffrey I. Victoroff, University of Southern California Keck School of Medicine, Chronicle of Higher Education "Wonderful."--Jacob N. Shapiro, Princeton University, Chronicle of Higher Education "[They] really help us refine our understanding of what the risk factors are."--Jessica Stern, Boston University Pardee School of Global Studies, Chronicle of Higher Education "Data-driven and carefully constructed."--John Waterbury, Foreign Affairs "Intriguing... There's a clear need to try and understand the motivation for this breed of terrorism that Gambetta and Hertog address in a thorough way that avoids alarmism."--Dominic Lenton, Engineering & Technology "Opening up markedly new perspectives on the motivations of political violence, Engineers of Jihad yields unexpected answers about the nature and emergence of extremism."--Islam and Muslim Societies "This relatively small book breaks significant new ground and should generate many more significant studies in this area. It should prove to be an important waystation on the path to better understanding not only of violent Islamism but of other political and politico-religious phenomena. It deserves a wide readership among those seriously interested in these subjects."--William Shepard, Journal of Global Analysis

• Preface vii 1. The Education of Islamist Extremists 1 At the Origins 3 A Systematic Test 6 The Saudi Exception 19 Selection Effects 21 Conclusions 32 2. Relative Deprivation in the Islamic World 34 Frustrated Ambitions and Relative Deprivation 34 Beyond Egypt 38 Are Engineers Especially Deprived? 42 The Saudi Exception Again 52 Conclusions, and Facts That Do Not Fit 54 3. Relative Deprivation Probed 60 Western-Based Jihadis 60 Violent vs. Nonviolent Opposition 72 Religious vs. Secular Militants 76 Die-hard Militants vs. Defectors 80 Conclusions 83 4. The Ideology of Islamist Extremism Compared 85 Historical Links 86 Shared Values 88 Shared Tastes and Beliefs 90 Radical Ideologies Compared 94 Conclusions 98 5. The Education of Other Extremists 100 Left-wing Extremists 101 Right-wing Extremists 106 Are the Dividing Lines Robust? 113 Extremists Compared: Islamists, Leftists, and Rightists 120 Conclusions and Summary So Far 125 6. Mind-sets for Extremists 128 Traits for Types of Extremists 129 The Three Traits among Graduates 134 Enter Women 141 One More Trait: "Simplism" 146 Traits and Disciplines 150 Conclusions 154 7. Conclusions 159 Bibliography 167 Index 185

Diego Gambetta is professor of social theory at the European University Institute, Florence, and official fellow of Nuffield College at the University of Oxford. His books include The Sicilian Mafia and Codes of the Underworld (Princeton). Steffen Hertog is associate professor of comparative politics at the London School of Economics. He is the author of Princes, Brokers, and Bureaucrats.

One of Foreign Affairs' Best Books on the Middle East (Terrorism & Counterterrorism) 2016 "This is an important study... The wealth of statistical data they bring to bear provides what was once a hypothesis with solid empirical grounding."--Malise Ruthven, Financial Times "[A]n interesting and important book... Definitely recommended."--Tyler Cowen, Marginal Revolution "That's really good work, and they deserve credit for that observation... It is thrilling and intriguing as a theoretical issue."--Jeffrey I. Victoroff, University of Southern California Keck School of Medicine, Chronicle of Higher Education "Wonderful."--Jacob N. Shapiro, Princeton University, Chronicle of Higher Education "[They] really help us refine our understanding of what the risk factors are."--Jessica Stern, Boston University Pardee School of Global Studies, Chronicle of Higher Education "Data-driven and carefully constructed."--John Waterbury, Foreign Affairs "Intriguing... There's a clear need to try and understand the motivation for this breed of terrorism that Gambetta and Hertog address in a thorough way that avoids alarmism."--Dominic Lenton, Engineering & Technology "Opening up markedly new perspectives on the motivations of political violence, Engineers of Jihad yields unexpected answers about the nature and emergence of extremism."--Islam and Muslim Societies "This relatively small book breaks significant new ground and should generate many more significant studies in this area. It should prove to be an important waystation on the path to better understanding not only of violent Islamism but of other political and politico-religious phenomena. It deserves a wide readership among those seriously interested in these subjects."--William Shepard, Journal of Global Analysis

• Preface vii 1. The Education of Islamist Extremists 1 At the Origins 3 A Systematic Test 6 The Saudi Exception 19 Selection Effects 21 Conclusions 32 2. Relative Deprivation in the Islamic World 34 Frustrated Ambitions and Relative Deprivation 34 Beyond Egypt 38 Are Engineers Especially Deprived? 42 The Saudi Exception Again 52 Conclusions, and Facts That Do Not Fit 54 3. Relative Deprivation Probed 60 Western-Based Jihadis 60 Violent vs. Nonviolent Opposition 72 Religious vs. Secular Militants 76 Die-hard Militants vs. Defectors 80 Conclusions 83 4. The Ideology of Islamist Extremism Compared 85 Historical Links 86 Shared Values 88 Shared Tastes and Beliefs 90 Radical Ideologies Compared 94 Conclusions 98 5. The Education of Other Extremists 100 Left-wing Extremists 101 Right-wing Extremists 106 Are the Dividing Lines Robust? 113 Extremists Compared: Islamists, Leftists, and Rightists 120 Conclusions and Summary So Far 125 6. Mind-sets for Extremists 128 Traits for Types of Extremists 129 The Three Traits among Graduates 134 Enter Women 141 One More Trait: "Simplism" 146 Traits and Disciplines 150 Conclusions 154 7. Conclusions 159 Bibliography 167 Index 185

Diego Gambetta is professor of social theory at the European University Institute, Florence, and official fellow of Nuffield College at the University of Oxford. His books include The Sicilian Mafia and Codes of the Underworld (Princeton). Steffen Hertog is associate professor of comparative politics at the London School of Economics. He is the author of Princes, Brokers, and Bureaucrats.

One of Foreign Affairs' Best Books on the Middle East (Terrorism & Counterterrorism) 2016 "This is an important study... The wealth of statistical data they bring to bear provides what was once a hypothesis with solid empirical grounding."--Malise Ruthven, Financial Times "[A]n interesting and important book... Definitely recommended."--Tyler Cowen, Marginal Revolution "That's really good work, and they deserve credit for that observation... It is thrilling and intriguing as a theoretical issue."--Jeffrey I. Victoroff, University of Southern California Keck School of Medicine, Chronicle of Higher Education "Wonderful."--Jacob N. Shapiro, Princeton University, Chronicle of Higher Education "[They] really help us refine our understanding of what the risk factors are."--Jessica Stern, Boston University Pardee School of Global Studies, Chronicle of Higher Education "Data-driven and carefully constructed."--John Waterbury, Foreign Affairs "Intriguing... There's a clear need to try and understand the motivation for this breed of terrorism that Gambetta and Hertog address in a thorough way that avoids alarmism."--Dominic Lenton, Engineering & Technology "Opening up markedly new perspectives on the motivations of political violence, Engineers of Jihad yields unexpected answers about the nature and emergence of extremism."--Islam and Muslim Societies "This relatively small book breaks significant new ground and should generate many more significant studies in this area. It should prove to be an important waystation on the path to better understanding not only of violent Islamism but of other political and politico-religious phenomena. It deserves a wide readership among those seriously interested in these subjects."--William Shepard, Journal of Global Analysis

• Preface vii 1. The Education of Islamist Extremists 1 At the Origins 3 A Systematic Test 6 The Saudi Exception 19 Selection Effects 21 Conclusions 32 2. Relative Deprivation in the Islamic World 34 Frustrated Ambitions and Relative Deprivation 34 Beyond Egypt 38 Are Engineers Especially Deprived? 42 The Saudi Exception Again 52 Conclusions, and Facts That Do Not Fit 54 3. Relative Deprivation Probed 60 Western-Based Jihadis 60 Violent vs. Nonviolent Opposition 72 Religious vs. Secular Militants 76 Die-hard Militants vs. Defectors 80 Conclusions 83 4. The Ideology of Islamist Extremism Compared 85 Historical Links 86 Shared Values 88 Shared Tastes and Beliefs 90 Radical Ideologies Compared 94 Conclusions 98 5. The Education of Other Extremists 100 Left-wing Extremists 101 Right-wing Extremists 106 Are the Dividing Lines Robust? 113 Extremists Compared: Islamists, Leftists, and Rightists 120 Conclusions and Summary So Far 125 6. Mind-sets for Extremists 128 Traits for Types of Extremists 129 The Three Traits among Graduates 134 Enter Women 141 One More Trait: "Simplism" 146 Traits and Disciplines 150 Conclusions 154 7. Conclusions 159 Bibliography 167 Index 185